1. Field of the Invention
The invention relates to a transmission chain for toys, more particularly to a length-adjustable transmission chain.
2. Description of the Related Art
Referring to FIG. 1, a conventional toy 1 with a gear transmission assembly 13 is shown to comprise a base building block 11 with an array of connecting holes 111, two supporting building blocks 12 spaced apart from each other and mounted removably on a top surface of the base building block 11 through the engagement between the connecting holes 111 in the base building block 11 and connecting posts (not shown) of the supporting building blocks 12, and a gear transmission assembly 13 provided removably on the supporting building blocks 12. The supporting building block 12 is formed with a plurality of holes 121 for mounting the connecting transmission shafts 16xe2x80x2, 16xe2x80x3 of the gear transmission assembly 13. The gear transmission assembly 13 includes a plurality of large-diameter gears 14, 14xe2x80x2, 14xe2x80x3 and a plurality of small-diameter gears 15, 15xe2x80x2 mounted on the connecting transmission shafts 16xe2x80x2, 16xe2x80x3.
Since the aforesaid toy 1 with the gear transmission assembly 13 requires direct engagement between the adjacent gears 14, 14xe2x80x2, 14xe2x80x3, 15, 15xe2x80x2, the spatial configuration thereof is limited.
Referring to FIG. 2, another conventional toy 2 with a belt transmission assembly 23 is shown to comprise a base building block 21, two supporting building blocks 22 engaging removably each other and mounted removably on the base building block 21 in a manner similar to the toy 1 of FIG. 1, a belt transmission assembly 23 reomvably mounted on the supporting building blocks 22, and a drive assembly 24 mounted on the base building block 21. The drive assembly 24 provides power to drive the belt transmission assembly 23.
The belt transmission assembly 23 includes wheels 232, 233, 235, 237, connecting transmission shafts 231, 236, 241 and belts 234, 238. Although the wheels 232, 233, 235, 237, the connecting transmission shafts 231, 236, 241 and the belts 234, 238 cooperatively provide more diverse configurations as compared to the prior art shown in FIG. 1, since the lengths of the belts are specified in accordance with the sizes of the wheels and the distance therebetween, the diversity of the belt transmission assembly 23 is still restricted. Moreover, the belts 234, 238 used in the belt transmission assembly 23 are generally made of rubber, and are thus susceptible to elastic fatigue after a period of use.
Therefore, the object of the present invention is to provide a length-adjustable transmission chain that is suitable for training on different sizes of sprockets and that is clear of the aforesaid drawbacks of the prior art.
Accordingly, the transmission chain of this invention comprises a plurality of unitary chain links, each of which has parallel first and second side plates, first and second connecting pins, first and second pivot pins, and first and second pivot seats.
The first and second side plates extend in a first direction and are spaced apart from each other in a second direction transverse to the first direction. Each of the first and second side plates has a first end portion and a second end portion opposite to the first end portion in the first direction.
The first connecting pin extends in the second direction and is connected integrally to the first end portions of the first and second side plates. The second connecting pin extends in the second direction and is connected integrally to the second end portions of the first and second side plates.
The first and second pivot pins protrude in opposite directions from the first end portions of the first and second side plates, respectively. The first and second pivot seats are formed integrally and respectively on the second end portions of the first and second side plates.
The first and second pivot pins of one of the chain links are connected pivotally, removably and respectively to the first and second pivot seats of an adjacent one of the chain links.